The invention relates in general to an arrangement for wireless signal transmission from a rotating body to a stationary receiving station. A detector is mounted in the rotating body in order to detect a change in the working condition of an item carried by the rotating body. If such a change has been detected a signal is given to a transmitter of the rotating body. The transmitter sends an information to a receiving station.
From U.S. Pat. No. 4,090,802 a chuck is known having a safety clutch so as to prevent overload resulting from broken or dull tools. In case of an overload the safety clutch is operated, closing a switch whereby a transmitter is energized by an accumulator within the chuck housing and generates a high frequency signal which is transmitted to a receiver remotely mounted from the chuck so as to present an audio, optical display or can actually turn off the machine provided with the chuck.
However, by this known concept only a yes-or-no information can be detected and transmitted.
According to another prior art a pressure sensitive element is mounted stationary in a machine head so as to be loaded by the reaction force of the tool. The output of the pressure sensitive element is amplified and transmitted to a display. Indeed a continuous control of the reaction force of the tool is achieved thereby however, because the detector is arranged in the stationary machine head and not in the rotating spindle itself, the detected values are inaccurate and for example influenced by the friction of the bearing. Malfunctions can occur by vibrations of the machine and other influences.